Thread (9 messages) 9 messages, 5 authors, 2021-10-24

Re: [PATCH v6 2/2] pinctrl: microchip sgpio: use reset driver

From: Philipp Zabel <p.zabel@pengutronix.de>
Date: 2021-10-18 10:37:35
Also in: linux-devicetree, linux-gpio, lkml

Hi Horatiu,

On Mon, 2021-10-18 at 10:57 +0200, Horatiu Vultur wrote:
quoted hunk ↗ jump to hunk
On lan966x platform when the switch gets reseted then also the sgpio
gets reseted. The fix for this is to extend also the sgpio driver to
call the reset driver which will be reseted only once by the first
driver that is probed.

Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
---
 drivers/pinctrl/pinctrl-microchip-sgpio.c | 7 +++++++
 1 file changed, 7 insertions(+)
diff --git a/drivers/pinctrl/pinctrl-microchip-sgpio.c b/drivers/pinctrl/pinctrl-microchip-sgpio.c
index 072bccdea2a5..78765faa245a 100644
--- a/drivers/pinctrl/pinctrl-microchip-sgpio.c
+++ b/drivers/pinctrl/pinctrl-microchip-sgpio.c
@@ -17,6 +17,7 @@
 #include <linux/pinctrl/pinmux.h>
 #include <linux/platform_device.h>
 #include <linux/property.h>
+#include <linux/reset.h>
 
 #include "core.h"
 #include "pinconf.h"
@@ -803,6 +804,7 @@ static int microchip_sgpio_probe(struct platform_device *pdev)
 	int div_clock = 0, ret, port, i, nbanks;
 	struct device *dev = &pdev->dev;
 	struct fwnode_handle *fwnode;
+	struct reset_control *reset;
 	struct sgpio_priv *priv;
 	struct clk *clk;
 	u32 val;
@@ -813,6 +815,11 @@ static int microchip_sgpio_probe(struct platform_device *pdev)
 
 	priv->dev = dev;
 
+	reset = devm_reset_control_get_optional_shared(&pdev->dev, "switch");
This is the first GPIO driver that I am aware of that requests a named
reset control, so I'm still not sure if this should be called "switch"
instead of "gpio" or just "reset", just in case there is a future model
where the GPIO controller reset is not shared with the switch reset.
+	if (IS_ERR(reset))
+		return dev_err_probe(dev, PTR_ERR(reset), "Failed to get reset\n");
+	reset_control_reset(reset);
+
 	clk = devm_clk_get(dev, NULL);
 	if (IS_ERR(clk))
 		return dev_err_probe(dev, PTR_ERR(clk), "Failed to get clock\n");
But whichever name you choose, the code is

Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>

regards
Philipp

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